There is no "should" or "should not". The depends on the question that you are trying to answer.
It might be easier to use the percent equation rather than the percent proportion when you are multiplying and dividing.
An equation that states that two ratios are equal is a proportion.
Such an equation is called a "proportion".
A percent is simply a proportion out of 100.
a proportion is an equation. a / b = c / d cross multiply: ad = bc then solve
The percentage is 100 times the proportion.
Converting a ratio to a percent is not the same as solving a proportion.
a proportion
It is the value which represents the proportion as a part of 100.
Wavelength and frequency are inversely proportional in the wavelength-frequency equation. This means that as the wavelength of a wave increases, the frequency decreases, and vice versa.
If each side of the equation is a fraction, then it is a proportion.